INTRODUCTION For the last decade, there has been a steady increase in the glob- al acreage of transgenic commercial crops. In 1998 it was esti- mated that there were over 28 million ha of transgenic com- mercial crops grown worldwide, excluding China (James, 1998). Because honey bees (Apis mellifera) play critical roles in pollinat- ing fruits and vegetables (Morse & Calderone, 2001), many stud- ies have been conducted to evaluate the effect of transgenic products on honey bees (reviewed by Malone & Pham-Delègue et al. 2001). The majority of studies on the effects of transgenic crops on honey bees have used purified transgene products, i.e. proteins. There have been five laboratory studies done on purified Bacil- lus thuringiensis (Bt) proteins (Sims, 1995; Arpaia, 1996; Malone et al., 1999; US Environmental Protection Agency, 2000; Malone et al., 2001). Nine studies tested the effects of serine protease inhibitors on honey bees (Belzunces et al., 1994; Malone et al., 1995; Burgess et al., 1996; Malone et al., 1998; Girard et al., 1998; Jouanin et al., 1998; Malone et al., 1999; Pham-Delègue et al., 2000; Malone et al., 2001). The effects of other proteins such as chitinase, ß-1,3 glucanase and avidin have been tested in labora- tory studies (Picard-Nizou et al., 1997; Malone et al., 2002). There have been only two published studies that used intact pollen instead of purified transgene proteins (Jouanin et al., 1998; Schur et al., 2000; cited in Malone & Pham-Delègue, 2001). While it is important to determine the potential detrimental effects of transgene products on honey bees, it is also important to determine whether pollen from transgenic plants has nega- tive effects on honey bees. This is because there might be other new proteins expressed in the transgenic plants besides the transgene product(s), due to either pleiotropic effects of the inserted genes (Uberlacker et al., 1996), alternative splicing (Lopato et al., 1999), or other mechanisms such as interactions between host genes and inserted genes (Kohli et al., 1998). Because some Bt toxins (such as Cry1A(b) and Cry1F) target lepidopteran insects and honey bees store large amounts of pollen in the hive (Winston, 1987), we suspect that Bt corn pollen could be an alternative control method against the greater wax moth (Galleria mellonella). The greater wax moth is an important pest of honey bees. Larvae of the greater wax moth cause considerable damage to beeswax combs left unattended by bees. Beeswax combs in weak or dead colonies and those placed in storage are subject to attack (Caron, 1999). Although there are other methods available for controlling this pest (Cantwell, 1981), Bt corn pollen, if effective at killing wax moth, would be economical and unlikely to contaminate honey or beeswax as do current fumigant control methods. The objectives of this study were two-fold: (1) to determine the effect of Bt corn pollen on honey bee worker larvae, and (2) to evaluate Bt corn pollen as a potential control of the greater wax moth. MATERIALS AND METHODS Honey bee pollen-feeding studies Corn pollen was collected during corn tasseling in late July or early August (2000 and 2001), depending on the variety of corn, from commercial farms (regular corn or Cry1A(b) corn), or Michigan State University (USA) experimental farms (Cry1F corn). Corn tassels were bagged (Lawson No. 402 - Shower- proof’d ® ) in the early morning or in the afternoon when tassels began to shed pollen. On the following day, the bags were invert- ed, tapped to release the pollen and removed. After the bags *Corresponding author: pett@msu.edu Journal of Apicultural Research 42(4): 77–81 (2003) © IBRA 2003 ORIGINAL ARTICLE Effects of dietary transgenic Bt corn pollen on larvae of Apis mellifera and Galleria mellonella ANNE V HANLEY , 1 ZACHARY Y HUANG 1,2 AND WALTER L PETT 1 * 1 Department of Entomology, Michigan State University, East Lansing, MI 48824, USA 2 Ecology, Evolutionary Biology and Behavior Program, Michigan State University, East Lansing, MI 48824, USA Received 4 April 2003, accepted subject to revision 13 August 2002, accepted for publication 21 August 2003 SUMMARY The effects of dietary transgenic Bt corn pollen on 4–5-day-old honey bee worker larvae were examined. We measured larval and pupal mortalities, pupal weight, and haemolymph protein concentration of newly emerged adults after they were fed (as larvae) various pollens (mixed bee pollen, non-transgenic corn pollen, Cry1A(b) or Cry1F corn pollen). There were no significant differences in all the parameters tested between larvae fed transgenic Bt corn pollen Cry1A(b) or Cry1F and non-transgenic corn pollen. We also evaluated Bt corn pollen as a potential control for wax moth larvae in a laboratory study. We fed first instar wax moth larvae three types of pollen: non-transgenic corn pollen, Cry1A(b) corn pollen, and Cry1F corn pollen. We found that the mortality of larvae fed Cry1F corn pollen was significantly greater than the mortality of larvae fed Cry1A(b) corn pollen or non-transgenic corn pollen (P < 0.05). In each trial Cry1F fed larvae showed 100% mortality. Our studies suggest that transgenic Bt corn pollen does not pose a threat to honey bee larval development and has the potential to serve as an alternative control for wax moth. Keywords: Bacillus thuringiensis, Bt corn pollen, greater wax moth, Galleria mellonella, honey bees Apis mellifera, transgenic pollen